Many polygons appear on the screen at the start of some day

What I expected to happen was...:
Nothing it was only the start of the day when the bug appear.

What actually happened was...:
many colored polygon appear on the screen. They move when I deplace my character.

Steps to Reproduce:
The bug appeared two time and the two time it was the start of the day, but it didn't appear every day sart.
The bug disappear when I go back to the main menu of the game but it restart when I launch the map. I need to close the game to remove the bug.
Pictures of the bug in "attachement".